Recent Advances in Flexible Pressure Sensors Based on MXene Materials

Abstract

In the past decade, with the rapid development of wearable electronics, medical health monitoring, internet of things and flexible intelligent robots, flexible pressure sensors have received unprecedented attention. As a very important kind of electronic components for information transmission and collection, flexible pressure sensor has gained a wide application prospect in the fields of aerospace, biomedical and health monitoring, electronic skin and human‐machine interface. In recent years, MXene has attracted extensive attention because of its unique two‐dimensional layered structure, high conductivity, rich surface terminal groups and hydrophilicity, which has brought a new breakthrough for flexible sensing. Thus, it has become a revolutionary pressure sensitive material with great potential. In this work, the recent advances of MXene‐based flexible pressure sensors is reviewed from the aspects of sensing type, sensing mechanism, material selection, structural design, preparation strategy and sensing application. The methods and strategies to improve the performance of MXene‐based flexible pressure sensors are analyzed in details. Finally, the opportunities and challenges faced by MXene‐based flexible pressure sensors are discussed. This review will bring the research and development of MXene‐based flexible sensors to a new high level, promoting the wider research exploitation and practical application of MXene materials in flexible pressure sensors.This article is protected by copyright. All rights reserved

Body-attachable multifunctional electronic skins for bio-signal monitoring and therapeutic applications

“…organ in the human body, continuously receives various forms of mechanical strains (e.g., bending, stretching, compressing, and twisting) during everyday movements. Wearable strain sensors are usually divided into three main categories based on their working principles: piezoresistive, capacitive, and piezoelectric effects [Figure 3A] [34] . Piezoresistive type sensors comprise conductive or semiconductor layers between two electrodes and transform the applied force into a resistance signal.…”

“…Capacitance C of the capacitive type sensors is conformed to the capacitance of parallel plate capacitors calculated by: where ε represents the dielectric constant, A is the electrode-active layer overlapping area, and d is the interval between two plates. With the same active layer material, interval length changes of the two [34] . Copyright 2020, Elsevier; (B) Fabrication method of PEDOT on a PS fiber for realizing textile sensors; (C) Optical images of linear-and zigzag-type textile strain sensors embedded in fabrics.…”

Boron/MXene Hollow Spheres for Humidity Sensing and Respiration Monitoring

“…To address this issue, benefiting from the electron–proton-coupled conduction process, introducing an additional electron-conducting phase could be an effective method. MXenes, such as Ti 3 C 2 T x , are an emerging class of 2D materials that possess both good electrical conductivity and surface activity imparted by the rich surface functional groups such as –F and –OH. − These surface terminal groups also impart high hydrophilic and surface electronegativity to MXene. − Therefore, there is a reason to believe that a resistive-type humidity sensor based on boron nanosheets can be achieved by incorporating them with MXene for enhanced sensing performance. However, constructing hierarchical suprastructures from boron and MXene-based nanocomposites remains a challenge.…”

Laser Thermochemical Synthesis of MXene/Graphene Heterostructure for a Highly Sensitive Flexible Pressure Sensor

“…Flexible pressure sensors (FPS) have broad application prospects in healthcare, robotics, and human-computer interaction due to their advantages of miniaturization, easy integration, and lightweight. , Conductive materials for FPS, such as graphene, CNTs, CB, MXene, Ag NPs, polyaniline, hydrogel, and conductive composites, have good electrical conductivity and mechanical strength, but face the problems of high cost, complex process, and poor stability. − Therefore, laser-induced graphene (LIG) technology, which uses laser irradiation to transform insulating carbon sources into conductive and stable graphene-like structures, has attracted tremendous attention as a low-cost, efficient, roll-to-roll preparation method. , For example, Lu prepared a LIG/hydrogel composite with excellent tensile properties and used it for mechanical and humidity sensing . Yu prepared an ultrathin, graphene-in-polyimide strain sensor via laser-induced interfacial ablation of polyimide .…”